In June 2018, Alexander Kraenkl, had been diving in the Red Sea for 50 minutes before encountering the oceanic whitetip shark.

The 51-year-old spotted the predator swimming towards him and tried to grab the anchor rope to lift himself to safety – but it was too late.

The shark viciously bit Alexander’s right thigh, just below a safety item hanging from his dive vest.

Alexander, who resides in Austria, told Barcroft TV: “In that moment, when I tried to grab the line, I felt a really hard shock in the right side of my leg.

“I didn’t know what was going on. I looked down and at that moment, I saw the shark swimming away from me and I knew what had happened.

“I was feeling really distressed. I always told my wife there was no danger when swimming with sharks because she was always more afraid of what I was doing.

“I have been on more than 150 dives in my life and seen lots of sharks and have never witnessed this. It was the craziest thing that had ever happened to me.

“I started to really panic because I saw this green stuff seeping out of my costume, which was obviously my blood in the water. It was a really big bite from a great monster!”

Alexander was in need of urgent attention with his leg bleeding out and, thankfully, he was able to quickly parachute himself to safety on board their boat, with the shark swimming in the opposite direction.

Whitetip sharks inhabit tropical and warm temperature seas and are known for their stocky body and white-tipped rounded fins.

They are generally described as slow-moving, but aggressive – even picking up the label ‘the most dangerous of all sharks’ by some specialists.

“I quickly got myself to the surface,” Alexander said.

“I was trying to communicate and tell everyone I had been bitten by a shark. I was in shock. We were miles away from shore, I didn’t know how I would be treated.

“There was so much blood.

“I was very lucky the bite happened on my leg, where there aren’t that many nerves.

“At the same time, I was worrying what was going on in the water with the shark. I had family down there too. I was shouting, asking people on the boat to bring them up. I was hoping nothing was happening to them.”

Alexander’s brother-in-law, Georg Arnold, managed to film the captivating action on his recorder beneath the surface.

Georg, 56, continued to follow the shark’s movement after the attack, unsure of what had happened and that Alexander was trying to scurry to the surface.

Georg said: “Me and Alexander have been diving together for many years and we had never seen anything like this.

“I was super excited because I had never seen a shark like this before.

“I saw the shark close to Alex, but just thought it grazed his leg and was nothing serious.

“I saw others getting out of the water quickly, but the ladder was occupied. I was feeling uncomfortable because I had to wait my turn in the water with the shark still swimming around.

“Once I was back on board and Alex was treated, I was relieved but also super excited to know I had filmed it all.”

Alexander is very grateful to his family for their help and particularly the guide who was on standby to help contact a nearby doctor sailing on another boat.

It could well have been a different outcome for the Austrian without those people around him.

Alexander said: “The guide was really well prepared, she had everything on board that was needed to treat me.

“I had a couple of smaller bites in the inner side of my knee and then a really big wound in the middle of my upper leg.

“I was so lucky there was a doctor on another boat travelling near to us. We made a call and he was there in a few hours with a big box of sewing equipment.

“Overall, I had 40 to 50 stitches in my leg. I had a sip of vodka and every time they stitched, I had a small piece of that.”

Looking back on the footage, Alexander is thankful to still be here to tell his story – but it wasn’t enough to put him off diving forever.

“Now, people watch the video back and their reaction is always amazing,” he said.

“To stop diving – this thought never crossed my mind. I was just in the wrong position, at the wrong time. My wife is not so happy with this, I must add.